Concrete-mixer



H. R. 'LBEHNELJ CONCRETE MIXER.

APPLICATION FILED SEPT 13.1919

1,370,954, l l Patented Mar. 8, 1921.

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i UNITED STATES RALPH RAYMOND EBERSOLD, 0F CEDAR FALLS, IOWA.

CONCRETE-MIXER.

Specification of Letters Patent. -13a13ent3d Mar. 8, 1921.

Application led September 13, 1919. Serial lNo. 323,490.

T0 all w homy t may concern.'

Be it known that I, RALPH RAYMOND EBERsoLD, a citizen of the United States of America, and a resident of Cedar Falls, Blackhawk county, Iowa, have invented certain new and useful Improvements in C )oncrete-Mixers, of which the following is a specification.

Hy invention relates to improvements in concrete mixers, andthe Object of my irnprovement is to supply to machines for mixing concrete or other materials stirring, agitating, elevating and delivering devices within a rotatable mixing drum adapted to efciently and quickly mix materials within the drum and deliver the mixed product .to some receptacle suitably placedto receive it.

This object Iehave accomplished by the means which are hereinafter described and claimed, and which are illustrated .in the accompanying drawings, in which Figure 1'is i a vertical longitudinal axial section of the rotatable drum of my mixing machine, the contained and other structures associated therewith being shown in side elevation, and Fig. 2 is a transverse cross section of said drum taken on the broken line 2-2 of said Fig. 1, looking in the direction ofthe ar row, with other structures shown in fr ont elevation; Fig. 3 is a diagrammatic view of a part of one of the helices showing its angular relation to the radius and axis-of the drum, and Fig. 4 is a detail perspective view of one of the stirring blades or troughs with its associated pocket as related to a fragmentary part of the drum within which it is mounted.

Similar numerals of reference denote corresponding parts throughout the several views. l

The numeral 7 denotes a hollow cylindrical mixing drum rotatable on a horizontal axis by being mounted on grooved rollers 13 supported in standards 12 on a base 11, the grooves of said rollers receiving and traveling on the flat rings 14 fixed on the circumference of the drum near its heads. rlhe rear head of the drum has an axially positioned circular delivery opening 10. The chute 21, preferably in the form of a segment of a hollow cylinder, or longitudinally troughed, has on its under side a boss 23 fixed on the rock-shaft 20, the ends of the shaft being mounted in bearings 19 on transversely spaced supports 17. A hand lever 22 is fixed on said shaft for manually rocking it. The longer end of the chute is pro-4 jected forwardly a considerable distance into the interior of the drum 7 through its rear opening 10, and the hand lever may be used to rock said chute into a receiving l position as shown by the full lines, or into a downwardly tilted position as shown by the i dotted lines in said Fig. 1.

The numeral 9 denotes a circular axial receiving opening in the forward head of said drum, an outwardly offset rim 8 therefor being formed in said head to receive and prevent'egress of drippings from the inner wall of said head above while 'the drum is in rotation. e

The drum may be rotated byany desired or well known means such as a sprocket rim troughed spaces therebetween opening in the `r` direction of rotation of the drum. These blades or troughs are also longitudinally inclined obliquely along the inner circumferential wall of the drum and terminate in depressed receiving pockets 6 positioned against the rear head of the drum and also opening in the direction of rotation of the drum, but having a delivery part or lip in each case extending beyond the blade 4 into the interior of the drum. These parts 4 and 6 have an angularly directed strip 5 fitted closely to and secured to the inner circumferential wall of the drum, whereby said parts 4 and 6 supply a troughed receptacle extending across the drum.

The numerals 1 and 2 denote a pair of like fiat helices positioned within the drum coaxially, in reversed relation, that is, shaped like parts of widely pitched two thread surfaces of a screw whose sides have a triangular section. The diagram in Fig. 3 shows this inclining of the helices relative both to the axis b--Zi of the drum and a traversing radius a-a thereof. The angle of inclination of the helix surface may be any other than 90 degrees. It may be an angle of 25 degrees to the radius as shown in said figure, which would make the inclination 65 degrees to the axis. The forward or receiving ends of the helices 1 and 2 are close to the front head of the drum, but the other or delivery ends of the helices terminate immediately forward of the pockets 6.

The drum being in rotation, and the chute 21 tilted downwardly as shown by the dotted lines in Fig. l, material to be mixed being introduced through the front opening 9 is received partially by the helices and also by the troughs 4, the materials thus being divided, agitated and thrown back and forth in the drum moving longitudinally as also up and down when acted upon by said devices. Material in the ascending troughs 4 slides to the reartin each trough and into the pockets 6.* As the troughs become inverted during the rotation of the drum, the material in the pockets 6 falls upon the downwardly inclined end of the chute 21 which delivers it to the center of the drum. This operation continues until the material is sufliciently mixed. The chute 21 is then tilted to its discharging position shown in full lines in Fig. 1, and the material discharged from the pockets 6 during the further rotation of the drum is received and conveyed out of the drum by the chute.

The combination of diiferent stirring devices shownl exerts themaximum eiiect upon the contents of the drum which is conducive to rapid mixing as well as homogeneousness y in the mingled product.

The peculiarly inclined helix parts 1 and 2 being somewhat spread out, exercise a distributive and also a stirring action on the materials which could not be similarly associated devices within the drum, without departing from the invention. Either set of stirring means may be employed without the other, in drums of different types.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

A concrete mixer, comprising a horizontally rotatable hollow cylindrical mixing-drum having in its opposite heads central receivingand delivery-openings respectively, and means for rotating said drum; said drum having a plurality of oblique troughsV along its inner cylindrical wall terminating at the drumhead adjacent said deliveryopening in widened pockets, both the troughs and their terminal pockets opening into the interior of the drumtoward the direction of rotation thereof, and having like spiral segmental blades mounted therein oppositely in spaced relation to the inner circumferential wall to receive from said receiving-opening,` said blades being inclined from their inner to their outer longitudinal edges and to the axis of the drum to shatter unmixed materials Y received thereon and deliver them to said troughs as the drum rotates.

Signed at Waterloo, Iowa, this 3d day of September, 1919.

RALPH RAYMOND EBERSOLD. 

